Montana Sapphires

Can you tell us a little about the source of this material?

Montana Sapphires are one of today’s most sought after American-mined gems. This incredibly rare sapphire is mined in three distinct locations in Montana and known by different names. Many of the Montana Sapphires are either found in the gravels of the Missouri River in Lewis and Clark County, Rock Creek in Granite County and some even from Dry Cottonwood Creek. Each with small visual differences between location if you know what you’re looking for. Then you have Yogo Sapphires, which were discovered along Yogo Creek in the Little Belt Mountains of Montana. Most of these range in size from a grain of sand to the size of a pea. It is very rare that larger sized gems are found.

What kinds of sizes, shapes and cutting styles can be found?

We offer one of the widest varieties of shapes and sizes when it comes to Montana Sapphires. Many producers sacrifice brilliance for weight due to its value, but we prefer to optimize the cuts based on the raw rough material. This means we offer anything from calibrated melee rounds to baguettes, faceted hexagons, rose cuts, cushions, marquise, free form tablets, our signature GeoCut™, pears, kites and more.

Size is a very interesting part of the conversation when it comes to Montana Sapphires. Even the typical Montana Sapphire has a very skewed perception in the consumer market right now. Many people in the mass market expect to find large 1ct+ Montana Sapphires readily available, but the truth is that is extremely rare to find. So, you might ask what is the typical size? And how rare is it really for those larger 1ct+ stones?

With typical Montana Sapphires (Missouri River and Rock Creek material), the vast majority of production produces maybe up to 3/4ct and anything larger than that is extremely rare – maybe 5% of production would produce a stone larger than this. Now, with Yogos (from the Yogo Creek location), the ‘larger’ sizes are maybe 3-4mm! So, if you are asking about larger sizes in Yogo Sapphire, you’re talking about maybe a half-carat and those may go for $16,000-20,000/ct at retail.

To give an example, the image below is from one of our site-visits to a Montana mine we source rough from. The little pill bottle you see in the far left is the size container used when separating sapphire rough out of the “heavy rock” that settles in the jigs. This gives you an idea of how rare Montana Sapphires really are. Now, within that little pill bottle, there was maybe one single piece of rough that would be able to cut a carat sized stone. That shows you the extreme rarity it is to find a 1ct+ sized Montana Sapphire.

Is this material typically enhanced in any way?

Often times, Montana Sapphires are heated to remove silk (microscopic inclusions that to the eye may give a whitish sheen, resembling silk fabric) and improve color. Heat enhancement is stable, routine, and does not require special care, but knowing your supplier with heat treatment can be important. At Columbia Gem House, we have an in-house heat treatment process that we do ourselves. This means we can guarantee the treatment is heat-only. We also never use any foreign materials, like beryllium which would diffuse into the natural gems and create drastic color changes.

There are times when Montana Sapphires, as well as all of the Yogo Montana Sapphires, have no treatment whatsoever. That is why we always disclose any and all treatments on each of our gems, so you know exactly what you’re getting.

Are there any unique characteristics you can share about this material?

Montana Sapphires are members of the corundum family, which includes both ruby and sapphire. These gems have a hardness of 9 on the Mohs scale, making it a perfect color alternative for engagement rings. The clarity of Montana Sapphires may range from no visible inclusions to moderately included, and what’s particularly unique about Montana Sapphires are the colors! Montana Sapphires come in nearly every color of the rainbow.

Rich blues to fancy pinks and everything in between. Not to be missed are the Kaleidoscope™ Sapphires; unique to this region, they display up to three distinct colors in a single gem! Bi-colors are another popular colorway in which two distinct colors can be seen.

What are the gem specs of this material? How do we know if it is authentic?

The material we source at Columbia Gem House is backed with our Gem Trust guarantee. This means you know it’s an authentic gemstone and that we will share all available information with you. You can find additional gem specifications below:

Gem Type
Montana Sapphire
Fair Trade Level
Not treated or Heat-Only
Hardness (Mohs Scale)

How do I care for my gemstone?

Sapphire is among the most durable of gemstones. In its common form, corundum is even used as an abrasive! Clean your Montana Sapphire with warm water, detergent, and a soft brush. These gems can also be put in ultrasonic or steam cleaners.

What can you tell us beyond the facets? I want to know more…

Rock Creek Montana Sapphire’s true beauty was recognized when they were included in a line of fine jewelry created by Tiffany & Co. that was shown at the 1900 Paris Exposition. No longer considered to be of lesser value than the blues, the fancy-colored sapphires from Rock Creek took the world by storm, and caused even Tiffany & Co. gemologist George F. Kunz to wax poetic about their beauty in a 1901 publication:

"At no known locality, however, has there ever been found so great a variety of rich colors in corundum gems as here [Rock Creek]. At the Paris Exposition of 1900, there was shown a brooch of over 200 of these stones, ranging from 1 to 3 carats each, every one of a different tint or shade. Although the deep-red ruby and the "velvet blue" or "cornflower" sapphire were lacking, yet the richness and variety of the other kinds were unequaled; pale rubies, pink, salmon passing into yellow, pure yellow, yellow brown, and deep brown, pale blues and greens, blue green, etc. Often a single stone would show two or three distinct shades of one color. Many of the colors have never been observed at any other locality. All were of unusual brilliancy, and improve greatly in artificial light. The butterflies and other rich jewels made from these stones possess almost the beauty of natural insects."